org.springframework.beans.factory.xml
Class AbstractBeanDefinitionParser

java.lang.Object
  extended by org.springframework.beans.factory.xml.AbstractBeanDefinitionParser
All Implemented Interfaces:
BeanDefinitionParser
Direct Known Subclasses:
AbstractSingleBeanDefinitionParser, EmbeddedDatabaseBeanDefinitionParser, InitializeDatabaseBeanDefinitionParser

public abstract class AbstractBeanDefinitionParser
extends Object
implements BeanDefinitionParser

Abstract BeanDefinitionParser implementation providing a number of convenience methods and a template method that subclasses must override to provide the actual parsing logic.

Use this BeanDefinitionParser implementation when you want to parse some arbitrarily complex XML into one or more BeanDefinitions. If you just want to parse some XML into a single BeanDefinition, you may wish to consider the simpler convenience extensions of this class, namely AbstractSingleBeanDefinitionParser and AbstractSimpleBeanDefinitionParser.

Since:
2.0
Author:
Rob Harrop, Juergen Hoeller, Rick Evans, Dave Syer

Field Summary
static String ID_ATTRIBUTE
          Constant for the id attribute
static String NAME_ATTRIBUTE
          Constant for the name attribute
 
Constructor Summary
AbstractBeanDefinitionParser()
           
 
Method Summary
 BeanDefinition parse(Element element, ParserContext parserContext)
          Parse the specified Element and register the resulting BeanDefinition(s) with the ParserContext.getRegistry() BeanDefinitionRegistry} embedded in the supplied ParserContext.
protected abstract  AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext)
          Central template method to actually parse the supplied Element into one or more BeanDefinitions.
protected  void postProcessComponentDefinition(BeanComponentDefinition componentDefinition)
          Hook method called after the primary parsing of a BeanComponentDefinition but before the BeanComponentDefinition has been registered with a BeanDefinitionRegistry.
protected  void registerBeanDefinition(BeanDefinitionHolder definition, BeanDefinitionRegistry registry)
          Register the supplied bean with the supplied registry.
protected  String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)
          Resolve the ID for the supplied BeanDefinition.
protected  boolean shouldFireEvents()
          Controls whether this parser is supposed to fire a BeanComponentDefinition event after parsing the bean definition.
protected  boolean shouldGenerateId()
          Should an ID be generated instead of read from the passed in Element?
protected  boolean shouldGenerateIdAsFallback()
          Should an ID be generated instead if the passed in Element does not specify an "id" attribute explicitly?
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

ID_ATTRIBUTE

public static final String ID_ATTRIBUTE
Constant for the id attribute

See Also:
Constant Field Values

NAME_ATTRIBUTE

public static final String NAME_ATTRIBUTE
Constant for the name attribute

See Also:
Constant Field Values
Constructor Detail

AbstractBeanDefinitionParser

public AbstractBeanDefinitionParser()
Method Detail

parse

public final BeanDefinition parse(Element element,
                                  ParserContext parserContext)
Description copied from interface: BeanDefinitionParser
Parse the specified Element and register the resulting BeanDefinition(s) with the ParserContext.getRegistry() BeanDefinitionRegistry} embedded in the supplied ParserContext.

Implementations must return the primary BeanDefinition that results from the parse if they will ever be used in a nested fashion (for example as an inner tag in a <property/> tag). Implementations may return null if they will not be used in a nested fashion.

Specified by:
parse in interface BeanDefinitionParser
Parameters:
element - the element that is to be parsed into one or more BeanDefinitions
parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry
Returns:
the primary BeanDefinition

resolveId

protected String resolveId(Element element,
                           AbstractBeanDefinition definition,
                           ParserContext parserContext)
                    throws BeanDefinitionStoreException
Resolve the ID for the supplied BeanDefinition.

When using generation, a name is generated automatically. Otherwise, the ID is extracted from the "id" attribute, potentially with a fallback to a generated id.

Parameters:
element - the element that the bean definition has been built from
definition - the bean definition to be registered
parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry
Returns:
the resolved id
Throws:
BeanDefinitionStoreException - if no unique name could be generated for the given bean definition

registerBeanDefinition

protected void registerBeanDefinition(BeanDefinitionHolder definition,
                                      BeanDefinitionRegistry registry)
Register the supplied bean with the supplied registry.

Subclasses can override this method to control whether or not the supplied bean is actually even registered, or to register even more beans.

The default implementation registers the supplied bean with the supplied registry only if the isNested parameter is false, because one typically does not want inner beans to be registered as top level beans.

Parameters:
definition - the bean definition to be registered
registry - the registry that the bean is to be registered with
See Also:
BeanDefinitionReaderUtils.registerBeanDefinition(BeanDefinitionHolder, BeanDefinitionRegistry)

parseInternal

protected abstract AbstractBeanDefinition parseInternal(Element element,
                                                        ParserContext parserContext)
Central template method to actually parse the supplied Element into one or more BeanDefinitions.

Parameters:
element - the element that is to be parsed into one or more BeanDefinitions
parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry
Returns:
the primary BeanDefinition resulting from the parsing of the supplied Element
See Also:
parse(org.w3c.dom.Element, ParserContext), postProcessComponentDefinition(org.springframework.beans.factory.parsing.BeanComponentDefinition)

shouldGenerateId

protected boolean shouldGenerateId()
Should an ID be generated instead of read from the passed in Element?

Disabled by default; subclasses can override this to enable ID generation. Note that this flag is about always generating an ID; the parser won't even check for an "id" attribute in this case.

Returns:
whether the parser should always generate an id

shouldGenerateIdAsFallback

protected boolean shouldGenerateIdAsFallback()
Should an ID be generated instead if the passed in Element does not specify an "id" attribute explicitly?

Disabled by default; subclasses can override this to enable ID generation as fallback: The parser will first check for an "id" attribute in this case, only falling back to a generated ID if no value was specified.

Returns:
whether the parser should generate an id if no id was specified

shouldFireEvents

protected boolean shouldFireEvents()
Controls whether this parser is supposed to fire a BeanComponentDefinition event after parsing the bean definition.

This implementation returns true by default; that is, an event will be fired when a bean definition has been completely parsed. Override this to return false in order to suppress the event.

Returns:
true in order to fire a component registration event after parsing the bean definition; false to suppress the event
See Also:
postProcessComponentDefinition(org.springframework.beans.factory.parsing.BeanComponentDefinition), ReaderContext.fireComponentRegistered(org.springframework.beans.factory.parsing.ComponentDefinition)

postProcessComponentDefinition

protected void postProcessComponentDefinition(BeanComponentDefinition componentDefinition)
Hook method called after the primary parsing of a BeanComponentDefinition but before the BeanComponentDefinition has been registered with a BeanDefinitionRegistry.

Derived classes can override this method to supply any custom logic that is to be executed after all the parsing is finished.

The default implementation is a no-op.

Parameters:
componentDefinition - the BeanComponentDefinition that is to be processed